It seems to becoming harder to find netbook size laptops to use with the Kobuki base and so I’m looking into using the Intel NUC (e.g. NUC6i5SYH). I want fully autonomous operation where the Kobuki can dock and charge its batteries and the PC, so I wondered if anyone was aware of a power solution e.g. external battery that can connect to the Kobuki 19v output AND will allow the NUC to get a reading of the battery level e.g. via USB. Alternatively, is it possible to use a dc-dc converter with one of the other Kobuki power outputs (e.g. 12v 5A) to power the NUC?
Or if anyone knows of a good choice of small laptop to use then that might be preferable.
Have a look at the OpenUPS, it’s a DC-DC converter as well as UPS (6-30V input, 6-24V output). It supports multiple battery chemistries (e.g. Li-Po, SLA) and has an adjustable DC output.
It has a USB interface, and Linux drivers, supporting Network UPS Tools.
I’ve been using this device on my robot, I wrote a very simple Python ROS interface for this, which just publishes the charging state and individual Li-Po cell voltages. I’ll upload this script and link it on this thread when I get the chance (I’m currently away from my robot).
Thanks for the response. After posting I did end up looking at that and it looks like a good solution. Good to know that you have it up and running and that the Linux drivers work etc.
I’m thinking of using 6 of these batteries:
which based on my very quick calculations should drive a NUC for about 6 hours (assuming NUC consumes 15W)?
I asked the OpenUPS company if they could recommend any enclosures - did you find one that works well?
we have a NUCi7 on our Turtlebot. We ordered an i5 but got an i7 due to
some issue while ordering. The i5 had a notebook powerbank with it which
is not powerful enough for an i7 (it lasts about 30 minutes). Thus we
are now testing a custom LiIon battery. It seems to be able to run the
i7 for about 4-5 hours now but we are still working on a battery status
integration. Additionally, we need about 4-6A for charging the robot
now. From the internal wiring, this should not be a problem, but the
wall charger only gives us 3.2A. So we also still need to get a powerful
wall charger (right now using adjustable lab power supplies).
Once the battery runs well, I can send you our setup. The OpenUPS looks
very nice as well, especially the already integrated battery status and
charging state. If you deploy it to your Turtlebot, could you give
feedback about it?
We are also using Turtlebot (version 1) with an i7 NUC which actually requires 19V / 65 W. So far, we didn’t use any DC/DC converters or something similar, but instead, we powered the NUC directly from the 12V / 5A output port on the Kobuki.
This is certainly not ideal, and we experienced the NUC shutting down because of a “processor thermal trip” after some time (sometimes only 30 mins when the Kobuki battery would still last for long). First we thought it’s a problem with the NUC (old thermal paste or something), but later we realized that the output voltage from the Kobuki is monotonically decreasing and will be too low at some point. This seems to have caused the overheating problems then.
Either DCDC-NUC or OpenUPS seem like good solutions for this problem, but I’m not very experienced with DC-DC converters or UPS and I’m glad for any advice.
Can anyone tell me if this would be a good buy for more reliable mobile NUC operation?
We had a similar problem and solved it by purchasing a power bank. It charges from the kobuki base, provides 19V to the NUC and does not kill the Kobuki battery. We use one of the 19V connectors on the back of the Kobuki and make an adapter to charge the powerbank when the robot is on the charger.